This set of Hadoop Multiple Choice Questions & Answers (MCQs) focuses on “Data Flow”.

1. ________ is a programming model designed for processing large volumes of data in parallel by dividing the work into a set of independent tasks.
a) Hive
b) MapReduce
c) Pig
d) Lucene


2. Point out the correct statement :
a) Data locality means movement of algorithm to the data instead of data to algorithm
b) When the processing is done on the data algorithm is moved across the Action Nodes rather than data to the algorithm
c) Moving Computation is expensive than Moving Data
d) None of the mentioned


3. The daemons associated with the MapReduce phase are ________ and task-trackers.
a) job-tracker
b) map-tracker
c) reduce-tracker
d) All of the mentioned


4. The JobTracker pushes work out to available _______ nodes in the cluster, striving to keep the work as close to the data as possible
a) DataNodes
b) TaskTracker
c) ActionNodes
d) All of the mentioned


5. Point out the wrong statement :
a) The map function in Hadoop MapReduce have the following general form:map:(K1, V1) → list(K2, V2)
b) The reduce function in Hadoop MapReduce have the following general form: reduce: (K2, list(V2)) → list(K3, V3)
c) MapReduce has a complex model of data processing: inputs and outputs for the map and reduce functions are key-value pairs
d) None of the mentioned


6. InputFormat class calls the ________ function and computes splits for each file and then sends them to the jobtracker.
a) puts
b) gets
c) getSplits
d) All of the mentioned


7. On a tasktracker, the map task passes the split to the createRecordReader() method on InputFormat to obtain a _________ for that split.

a) InputReader
b) RecordReader
c) OutputReader
d) None of the mentioned


8. The default InputFormat is __________ which treats each value of input a new value and the associated key is byte offset.

a) TextFormat
b) TextInputFormat
c) InputFormat
d) All of the mentioned


9. __________ controls the partitioning of the keys of the intermediate map-outputs.
a) Collector
b) Partitioner
c) InputFormat
d) None of the mentioned


10. Output of the mapper is first written on the local disk for sorting and _________ process.
a) shuffling
b) secondary sorting
c) forking
d) reducing